Objectives of this project are to describe the socioeconomic and biomedical correlates among mothers and their children, of differential reproductive success in an urbanizing population of Chiang Mai, Thailand. This is the second phase of a longitudinal study begun in 1973. Reproductive performance (assessed by marital and reproductive history and in terms of fetal, infant and child survival and growth) and socioeconomic and biomedical variables (measured by occupational and educational history, living conditions, anthropometry, physical examination, nutritional and other laboratory tests) are examined in order to predict future trends in vital rates and child growth and development. BIBLIOGRAPHIC REFERENCES: Muecke, Marjorie A. "Reproductive Success" among urban poor: a micro-level study of infant survival and child growth in northern Thailand. Doctoral dissertation, Department of Anthropology, University of Washington, Seattle, 1976. Muecke, Marjorie A. Health care systems as socializing agents: child bearing the North Thai and Western ways. Social Science and Medicine 10 (7/8), July/August, 1976.